Merge pull request #36 from fabxc/master

fix go tarball download for OS X, use redirect from golang.org

Makefile

@@ -3,17 +3,30 @@ VERSION  := 0.7.1
 SRC      := $(wildcard *.go)
 TARGET   := node_exporter
 
-OS   := $(subst Darwin,darwin,$(subst Linux,linux,$(shell uname)))
-ARCH := $(subst x86_64,amd64,$(shell uname -m))
-
-GOOS   ?= $(OS)
-GOARCH ?= $(ARCH)
-GOPKG  := go1.4.1.$(OS)-$(ARCH).tar.gz
-GOROOT := $(CURDIR)/.deps/go
-GOPATH := $(CURDIR)/.deps/gopath
-GOCC   := $(GOROOT)/bin/go
-GOLIB  := $(GOROOT)/pkg/$(GOOS)_$(GOARCH)
-GO     := GOROOT=$(GOROOT) GOPATH=$(GOPATH) $(GOCC)
+OS         := $(subst Darwin,darwin,$(subst Linux,linux,$(shell uname)))
+ARCH       := $(subst x86_64,amd64,$(shell uname -m))
+
+# The release engineers apparently need to key their binary artifacts to the
+# Mac OS X release family.
+MAC_OS_X_VERSION ?= 10.8
+
+GOOS       ?= $(OS)
+GOARCH     ?= $(ARCH)
+
+ifeq ($(GOOS),darwin)
+RELEASE_SUFFIX ?= -osx$(MAC_OS_X_VERSION)
+else
+RELEASE_SUFFIX ?=
+endif
+	
+GO_VERSION ?= 1.4.1
+GOURL      ?= https://golang.org/dl
+GOPKG      ?= go$(GO_VERSION).$(GOOS)-$(GOARCH)$(RELEASE_SUFFIX).tar.gz
+GOROOT     := $(CURDIR)/.deps/go
+GOPATH     := $(CURDIR)/.deps/gopath
+GOCC       := $(GOROOT)/bin/go
+GOLIB      := $(GOROOT)/pkg/$(GOOS)_$(GOARCH)
+GO         := GOROOT=$(GOROOT) GOPATH=$(GOPATH) $(GOCC)
 
 SUFFIX  := $(GOOS)-$(GOARCH)
 BINARY  := $(TARGET)
@@ -24,7 +37,7 @@ default: $(BINARY)
 
 .deps/$(GOPKG):
 	mkdir -p .deps
-	curl -o .deps/$(GOPKG) https://storage.googleapis.com/golang/$(GOPKG)
+	curl -o .deps/$(GOPKG) -L $(GOURL)/$(GOPKG)
 
 $(GOCC): .deps/$(GOPKG)
 	tar -C .deps -xzf .deps/$(GOPKG)